1. Field of the Invention
This invention relates to an automatic telephone alarm system which, in the absence of certain signs of daily activity of the owner, namely his use of the telephone, will continuously dial prerecorded numbers and give messages of the emergency, or will initiate other types of alarms.
2. Description of the Prior Art
Many old or infirm people who live alone fear their becoming incapacitated, being unable to summon help, and perhaps expiring or suffering irremediable damage because they may not be found for days. There have been many efforts to arrange for periodic checks on isolated infirm persons by individuals or agencies to see if they are all right, but these checks are costly in terms of time and effort, and may be unreliable. Warning devices have also been developed to automatically call for help by telephone or other means if persons become stricken, but these have mostly involved positive actuating mechanisms which, of course, a severely incapacitated person might not be able to effectuate.
One patented alarm device (Rubinstein U.S. Pat. No. 3,662,111) is actuated by default of the owner. It generates low level alarms at predetermined time intervals which, if not reacted to by the owner, lead to a dialing and message alarm sequence. However, the periodic low level alarms, with requirement for action by the owner each time, could prove to be an annoyance to some persons. The owner must be present at each predetermined time each day, which is not an appropriate expectation for old but still active persons. Also, if the owner is sleeping, the predetermined alarms would wake him.
An alarm system developed in Sweden and referred to as "The Watchman" "Emergency Warning Aid (EWA)" utilizes a control unit connected to frequently used electric switches such as the bathroom or refrigerator light, the stove, or a bedside lamp. When the switch it turned on, an impulse is transmitted to the unit, setting a timer to zero. If the timer is not reset within a predetermined time, an alarm is transmitted. A disadvantage of this system is that the activity sensors are widely scattered throughout the abode and are separate and apart from the single most likely instrument for obtaining help -- the telephone. The installation of such a complicated system in different parts of a dwelling could be quite expensive.
There is need for a unitary device which is responsive to the possible incapacity of the owner, but also is responsive to this capable, usual daily functioning, and during such periods of capable functioning would remain a silent and unobtrusive guardian. If the device is to be of practical value it should be as simple and inexpensive as possible, to make it available to the elderly or disabled groups who need it. The device should be integrated with the household telephone which is habitually used on a daily basis by persons living alone and is thought of as the single most likely location in a dwelling where one can call for emergency assistance.